Impact of brain‐derived neurotrophic factor genetic polymorphism on cognition: A systematic review

Abstract

IntroductionBrain‐derived neurotrophic factor (BDNF) has an important role in the neurogenesis and neuroplasticity of the brain. This systematic review was designed to examine the association between BDNF Val66Met (rs6265) polymorphism and four cognitive domains—attention and concentration, executive function, verbal fluency, and memory, respectively.MethodologyPrimary literature search was performed using search engines such as PubMed and Scopus. Observational studies that evaluated the neurocognitive performances in relation to BDNF polymorphism within human subjects were included in this review, while animal studies, overlapping studies, and meta‐analysis were excluded.ResultsForty of 82 reviewed studies (48.8%) reported an association between Val66Met polymorphism and neurocognitive domains. The proportion of the studies showing positive findings in cognitive performances between Val/Val homozygotes and Met carriers was comparable, at 30.5% and 18.3%, respectively. The highest percentage of positive association between Val66Met polymorphism and neurocognition was reported under the memory domain, with 26 of 63 studies (41.3%), followed by 18 of 47 studies (38.3%) under the executive function domain and four of 23 studies (17.4%) under the attention and concentration domain. There were no studies showing an association between Val66Met polymorphism and verbal fluency. In particular, Val/Val homozygotes performed better in tasks related to the memory domain, while Met carriers performed better in terms of executive function, in both healthy individuals and clinical populations.ConclusionWhile numerous studies report an association between Val66Met polymorphism and neurocognitive changes in executive function and memory domains, the effect of Met allele has not been clearly established.

Single Nucleotide Polymorphisms in Thyroid Hormone Transporter Genes MCT8, MCT10 and Deiodinase DIO2 Contribute to Inter-Individual Variance of Executive Functions and Personality Traits

“…Since the SNPs of MCT8, MCT10 and DIO2 are crucial for the function of thyroid hormones, we were interested if they would also influence cognitive functions and personality traits. There are numerous instances in which an influence of polymorphisms, mostly in monoaminergic genes, on both, cognitive processes [38][39][40][41] and personality traits [42][43][44][45] has been shown which motivated our approach. Previous studies have also shown that the amount of variance that can be explained by single polymorphisms is rather modest.…”

The BDNF Val66Met Polymorphism Modulates Resilience of Neurological Functioning to Brain Ageing and Dementia: A Narrative Review

“…Conversely, a study using an auditory distraction paradigm-different, methodologically, from standard cognitive testing-has shown that BDNF Val homozygosity may be disadvantageous when inhibitory mechanisms are required, indicating that increased activation associated with the Val allele may not be advantageous for inhibitory effects processed in frontal pathways [40]. A recent systematic review on the topic has confirmed that BDNF Val66Met likely has some impact on cognitive function, although the specific direction is difficult to ascertain [41]. Additionally, Toh and colleagues [41] suggest that Met may be advantageous for executive functioning, although broader results are not consistent.…”

“…A recent systematic review on the topic has confirmed that BDNF Val66Met likely has some impact on cognitive function, although the specific direction is difficult to ascertain [41]. Additionally, Toh and colleagues [41] suggest that Met may be advantageous for executive functioning, although broader results are not consistent.…”

Adeno‐associated virus‐based Alzheimer's disease mouse models and potential new therapeutic avenues

“…BDNF promotes survival and functions of neurons. In AD, BDNF mRNA, and protein levels were found to be decreased, possibly contributing to memory deficits and neuronal loss (reviewed in Toh, Ng, Tan, Tan, & Chan, 2018;Zhao et al, 2017). Similarly, BDNF expression is lowered in neurodegenerative conditions with Tau pathology (Belrose, Masoudi, Michalski, & Fahnestock, 2014).…”